Transplantation is a rapidly-expanding, challenging area of clinical medicine with great potential for the cure of many human diseases. This field provides exciting opportunities for productive interaction between basic scientists and clinicians. The University of Pittsburgh's Starzl Transplantation Institute and Departments in the School of Medicine provide a unique academic environment, conducive to the comprehensive, broad-based training of young basic scientists and physicians in transplantation biology, with an emphasis on immunology and cell and molecular pathology. Our Interdisciplinary Transplantation Biology Training Program trains graduate and postdoctoral researchers to help ensure that highly-trained investigators are available to assume leadership roles in academia, industry and government-affiliated research. Participating faculty with diverse but complementary research interests, a successful record of productive collaboration and a commitment to training young investigators, impart skills in transplantation biology. Most aspects are covered, including expertise in immunogenetics, aspects of ischemia-reperfusion injury, antigen-presenting cell, T and B cell biology, tolerance induction, liver immunology, biology of transplant infectious disease, chronic rejection, composite tissue transplantation, evolution of allo- and xenorecognition, xenotransplantation and novel therapeutic immunosuppressive agents/regimens. A unique feature of the Training Program is that investigations range from those in invertebrates and rodents to non-human primates and humans. The principal goal of this Training Program is to produce outstanding, potentially independent investigators, able to address fundamental questions in transplantation biology and equipped with appropriate survival and career development skills. Pre-doctoral trainees are selected from graduate students enrolled in the Interdisciplinary Biomedical Graduate Training Program at the University of Pittsburgh School of Medicine, who express interest in pursuing PhD research in transplantation biology. Based on the successes achieved during the initial funding period of this Training Grant and the availability of well-qualified applicants, support is requested for 3 pre-doctoral trainees in the 06 year and for 3 trainees in subsequent years, distributed between students in their 1st, 2nd, 3rd or 4th year of research. Postdoctoral trainees with MD, PhD, or MD/PhD degrees will be selected based on their outstanding potential and will be supported for 2 years. Support is requested for 3 postdoctoral trainees in the 06 year, and for 3 trainees in subsequent years.